#define _CRT_SECURE_NO_WARNINGS 
#include <stdio.h>
#include <assert.h>
char* my_strcat(char* str1, const char* str2)
{
	char* m = str1;
	assert(str1 && str2);
	while (*str1)
	{
		str1++;
	}
	while (*str1++ = *str2++);
	{
		;
	}
	return m;
}
int main()
{
	char arr1[20] = { "bit " };
	char arr2[] = { "is yyds!" };
	printf("%s", my_strcat(arr1, arr2));
	return 0;
}